JPH04304219A - Production of photocuring fragrant gel - Google Patents

Abstract

PURPOSE:To produce a fragrant gel which is excellent in heat resistance, maintains its fragrance for a long period, does not warp nor foam, and has an excellent appearance without using hardener or heating means. CONSTITUTION:The title gel is produced by mixing a photopolymerizable oligomer (e.g. one polymerizable by ultraviolet rays) with a photopolymerizable monomer to give a gel substrate material having a suitable viscosity, compounding the material with a perfume having a relatively low extinction coefficient, and irradiating the resulting compsn. with photoenergy such as ultraviolet rays.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a photocurable aromatic gel that is cured by irradiation with light energy such as ultraviolet rays.

0002

[Prior Art] In recent years, the number of car and indoor air fresheners has increased, and in addition to providing a pleasant fragrance, they also serve as accessories, and come in a wide variety of shapes, sizes, and materials. is commercially available. Among these, gel-type air fresheners have received high praise because they are easy to handle, can be adapted to any design, have a strong scent, and have a long-lasting fragrance. Water gel type, oil gel type using metal soap, type made by kneading fragrance into polyethylene or polypropylene, and type cured by adding hardening agent such as epoxy resin are used.

0003

[Problems to be Solved by the Invention] When using a conventional gel base material in a gel-type fragrance as described above,
Many products are manufactured by blending fragrances while heating and cooling to gel, or by heating and molding, and since the resin is melted at high temperatures, volatilization of fragrances due to heating is unavoidable. Therefore, there have been problems such as a large blending loss of perfume, an adverse effect on the working environment in the manufacturing plant, and deterioration of the perfume at high temperatures.

In addition, the oil gel type has the problem that the fragrance retention agent does not have a network structure, so it volatilizes quickly and has poor sustainability.Furthermore, the water gel type loses weight over time and changes its surface area, resulting in a change in fragrance tone. The problem is that it changes rapidly and easily falls off the formwork. In addition, even in the type that uses a hardening agent, the quality of the perfume changes due to the hardening agent, and depending on the hardening agent, the hardening agent has strong toxicity and odor, and there are problems in handling. Furthermore, when used in automobiles, the temperature inside the car may rise to about 80° C., and water gel and oil gel types have the disadvantage of melting, making them difficult to use in automobiles.

[0005] The present invention was made with the aim of solving these problems, and does not include a curing agent that would alter the quality of the fragrance, does not require the addition of heat during production, and has a heat-resistant temperature. The purpose of the present invention is to provide a method for producing a photocurable aromatic gel that can be used even in high-temperature locations such as inside a car.

[0006]

[Means for solving the problem] As a result of various studies in order to achieve the above objective, the viscosity was adjusted to an appropriate level by blending a photopolymerizable monomer with an oligomer that can be polymerized by irradiation with light energy such as ultraviolet rays. It has been found that very suitable results can be obtained by using a gel base material prepared by the above method.

That is, in the present invention, by mixing a photopolymerizable monomer with an oligomer having an unsaturated bond that can be polymerized by light energy, the overall viscosity can be increased to 1 at 25°C.
00 to 5,000 cps, a method for producing a photocurable aromatic gel, which comprises preparing a gel base material having a temperature of 0.00 to 5000 cps, blending a fragrance into the gel base material, and then irradiating it with light energy. It is.

[0008] Examples of the oligomer in the present invention include polyester acrylate, epoxy acrylate,
Urethane acrylate, alkyd resin acrylate,
Examples include spiran resin acrylate and silicone resin acrylate.

[0009] These oligomers are preliminarily blended with a photopolymerization initiator, photosensitizer, etc. at a concentration of about 3% so that they can be polymerized by light energy. Examples of the photopolymerization initiator and photosensitizer include the following.

Isobutyl benzoin ether, isopropyl benzoin ether, benzoin ethyl ether,
Benzoin methyl ether, 1-phenyl 1,2-propanedione-2-(o-ethoxycarbonyl)oxime, 2,2-dimethoxy-2-phenylacetophenone,
Hydroxycyclohexylphenylketone, diethoxyacetophenone, 2-hydroxy-2-methyl-1. Phenylpropan-1-one, benzophenone, chlorothioxanthone, 2-chlorothioxanthone, isopropylthioxanthone, 2-methylthioxanthone, chlorine-substituted benzophenone, halogen-substituted alkyl-aryl ketone, 1-hydroxycyclohexyl phenyl ketone,
(1-6-η-cumene) (η-cyclopentadienyl)
Iron (1+) hexafluorophosphate (1-), 2-methyl-[4
-(methylthio)phenyl]-2-morpholino-1-
propanone

The above-mentioned oligomer is a prepolymer called a multifunctional acrylate, and has an unsaturated bond that can be polymerized by light energy, and has high photocurability and is suitable for photocuring of gel base materials. This is effective in improving properties by increasing the crosslinking density of the cured film, but on the other hand, with gel base materials made only of this polyfunctional acrylate, the resin shrinks violently during curing, resulting in poor adhesion to the fragrance container. If the film is deteriorated or a thick film is formed, there will be a difference in the hardening of the upper and lower parts, which will cause warping due to the difference in shrinkage rate.

Furthermore, if only oligomers such as polyfunctional acrylate are blended, the viscosity is extremely high, causing the problem that bubbles are trapped when the fragrance is mixed, making it impossible to remove the bubbles. .

[0013] Therefore, by mixing an appropriate photopolymerizable monomer with this oligomer in an appropriate proportion,
The above-mentioned resin shrinkage problem, poor adhesion to the container, warpage problem, and the above-mentioned bubble generation problem can be solved all at once.

As the photopolymerizable monomer in the present invention, it is preferable to use esters such as acrylic acid, methacrylic acid, itaconic acid, etc. Among them, esters of low molecular weight monovalent, divalent, or trivalent alcohols have low viscosity. So,
They are particularly suitable as reactive diluents. Note that when ultraviolet rays are used as light energy, acrylic esters are much more preferable due to their reactivity. Specific examples of this photopolymerizable monomer are listed below.

Monofunctional acrylate monomers 2-ethylhexyl acrylate, 2-hydroxypropyl acrylate, tetrahydrofurfuryl acrylate, 2-hydroxyethyl acrylate, phenoxyethyl acrylate, nonylphenoxyethyl acrylate, tetrahydrofurfuryloxyethyl acrylate, tetrahydrofurfuryloxyhexane Norido acrylate, 1.3
- Acrylate of ε-caprolactone adduct of dioxane alcohol, 1,3-dioxolane acrylate, diphenyl-2-acryloyloxyethyl phosphate, diphenyl-2-methacryloyloxyethyl phosphate

Bifunctional acrylate monomers Hexanediol acrylate, neopentyl glycol diacrylate, diethylene glycol diacrylate, tripropylene glycol diacrylate, polyethylene glycol diacrylate, diacrylate of neopentyl glycol hydroxybivalate, diacrylate of neopentyl glycol adipate , 2(2-hydroxy-
1.1-dimethylethyl)-5-hydroxymethyl-5
-Ethyl-1,3-dioxane diacrylate, tricyclodecane dimethylol diacrylate, ε-caprolactone adduct, diacrylate of diglycidyl ether of 1,6-hexanediol

Polyfunctional acrylate monomers trimethylolpropane triacrylate, dipentaerythritol propionate triacrylate, hydroxybivalaldehyde-modified dimethylolpropane triacrylate, tetraacrylate of dipentaerythritol propionate, ditrimethylolpropane tetraacrylate, dipropionate Pentaacrylate of pentaerythritol, hexaacrylate of dipentaerythritol, ε-caprolactone adduct of pentaerythritol, diacrylate of propylenoxide adduct of neopentyl glycol, diacrylate of ethyleneoxide adduct of neopentyl glycol hydroxypivalate, propylene oxide of trimethylolpropane Cholyacrylate of adducts, pentaacrylate of 1,3-dioxanepentanol, hexaacrylate of ε-caprolactone adduct of dipentaerythritol, diacrylate of ε-caprolactone adduct of neopentyl glycol hydroxypivalate, tricyclodecane diacrylate Diacrylate of ε-caprolactone adduct of methylol

These photopolymerizable monomers are blended into the photopolymerizable oligomer, which is the prepolymer, in an appropriate ratio to lower the overall viscosity, and the viscosity at 25° C. is 100 to 50.
The gel base material is adjusted to a range of 0.00 cps.

If the viscosity of the gel base material is less than 100 cps, it will be difficult to cure it into a thick film by irradiation with light energy such as ultraviolet rays, and the photocuring speed will be slow, resulting in poor production efficiency. On the other hand, if the viscosity exceeds 5,000 cps, the filling speed will be slow and production efficiency will be poor.If the viscosity is high when mixing fragrances, it will easily trap bubbles and it will be difficult to avoid the generation of bubbles, and it will be difficult to remove the bubbles. If the resin is cured while containing these substances, the aesthetic appearance will be impaired. For the reasons mentioned above, it can be said that a gel base material with a viscosity of 100 to 5000 cps at 25°C is the most excellent in terms of handling properties, photocurability, finished appearance, etc.

By the way, if the purpose is simply to lower the viscosity of the photopolymerizable oligomer, methyl alcohol, ethyl alcohol, propyl alcohol, isopropyl alcohol, ethylene glycol, propylene glycol, methyl carbide can be used without using this photopolymerizable monomer. It is possible to incorporate solvents such as toll, methyl cellosolve, polyethylene glycol, and polyvinylpyrrolidone.

[0021] However, the addition of these solvents causes severe shrinkage of the resin during curing and causes extreme warping, and in both cases a large amount of irradiation energy such as ultraviolet rays is required to slow down curing. It is. Therefore, prolonged ultraviolet irradiation and temperature rises cause the fragrance to volatilize, resulting in blending losses, shortening the persistence of the fragrance, and causing deterioration of the fragrance. In addition, the combination of this diluent causes many problems, such as the resin itself becoming brittle and easily broken, and hardness not increasing.

Therefore, in the production method of the present invention, the above-mentioned diluent is not used, but a photopolymerizable monomer is blended as a reactive diluent into the photopolymerizable oligomer serving as the base resin, so that the overall viscosity is 25°C. 100~5000cps
They used a gel base material adjusted to fall within this range, and added a fragrance to it.

[0023] As for the fragrance used in the present invention, it is desirable that its extinction coefficient is below a predetermined value. A suitable condition is to use a fragrance with a value of 1.5 or less.

If the absorbance coefficient exceeds 1.5, the perfume absorbs a lot of light when irradiated with light energy, and the photopolymerization of photopolymerizable oligomers and monomers is inhibited, making it difficult to cure.

[0025] Therefore, the fragrance in the present invention includes:
It is desirable to use a blended fragrance containing a large amount of dihydromircenol, linalool, phenylethyl alcohol, etc. By using these fragrances, curing occurs smoothly, there is no deterioration of the fragrance, and a long-lasting aromatic gel is produced. It is possible.

[0026] To give an example of an unsuitable fragrance, when blending citrus fragrances, hexyl cinnamic aldehyde, β-ionone, citral, etc. have large absorption coefficients, so these compounds should not be mixed with resin. This is undesirable because it inhibits curing, requires a large amount of irradiation energy, and causes deterioration of the fragrance and loss of formulation.

[0027] The blending ratio of the above-mentioned fragrance is usually about 5 to 50% of the total amount. In other words,
If the amount is less than 5%, the aroma will be weak and will not last long, and if it is more than 50%, the light curing speed will be slow and the hardness will not increase even after curing. The best option is 10 to 3 because it increases the cost.
It is about 0%. However, since these fragrances are often a mixture of various aromatic substances, it is impossible to strictly determine the mixing ratio within a predetermined range, and the ratio can be selected as appropriate depending on preference and purpose. It is.

[0028] The above-described appropriate fragrance is added to the gel base material adjusted to an appropriate viscosity as described above, mixed thoroughly, and then filled into a fragrance container, and then exposed to ultraviolet light or other light. By irradiating energy and curing it, the desired aromatic gel can be obtained.

Ultraviolet curing is most suitable as this light energy irradiation method, and examples of this ultraviolet irradiation method include low-pressure mercury lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, metal halide lamps, gallium lamps, mercury-xenon lamps, flash lamps, Carbon arc lamps, tungsten lamps, radiation, electron beams, sunlight, etc. can be used.

[0030]

[Example] The photopolymerizable oligomers shown in column A of Table 1 and the photopolymerizable monomers shown in column B were mixed at the blending ratio of each experiment number shown in Table 1 to prepare a gel base material. Note that these photopolymerizable oligomers are preliminarily treated with 2.
The one containing 3% of 2-dimethoxy-2-phenylacetophenone was used. (The same applies to the comparative examples in Table 2) The viscosity of these at 25° C. was measured and was as shown in column C.

[0031] Next, various fragrances were blended into the above-mentioned blended gel base material as shown in column D of Table 1, and after thorough mixing, a diameter of 7.
The mixture was filled into a plastic container measuring 1 cm and 1 cm deep to a depth of 5 mm, and cured by irradiation with a high-pressure mercury lamp. The physical properties of each of the photocurable aromatic gels thus obtained are shown in column E of Table 1.

[0032]

[Table 1]

For comparison purposes, as shown in Table 2, experiments were conducted in which aromatic agents with too high absorbance or viscosity were blended, and in which simple ethanol was blended as a diluent. The physical properties of these comparative examples are shown in Table 2.
Shown in the column.

[0034]

[Table 2]

[0035] The extinction coefficients of the perfumes in column D of Tables 1 and 2 are the maximum gram extinction coefficients in the wavelength range of 290 to 370 nm.

[0036] The evaluation methods for the various physical properties in column E of Tables 1 and 2 are as follows. Note that "-" in the table indicates that determination is impossible. Curing property: Check whether it is uniformly cured to the bottom. Hardness: Measured with a JIS-A type hardness meter. Shrinkage status of the resin: Check to see if it has shrunk and separated from the side of the plastic container. Warping of resin; Visual evaluation Persistence of fragrance; 0.5 when left in the back of an ordinary car
Carry out a box test every month to evaluate the persistence of the fragrance.Bubbles envelopment condition; visual evaluation

As shown in Table 1, all of the examples of the present invention are highly evaluated in terms of physical properties, but as shown in the comparative example in Table 2, there are cases where the viscosity of the gel base material is inappropriate or the light absorption of the fragrance If the coefficient was too large, or if a diluent was added, the fragrance could not be suitable.

[0038]

[Effects of the Invention] An advantage of the present invention is that it provides a method for producing a gel-type fragrance that does not require the addition of a curing agent that would alter the quality of the fragrance or the need for heating during production. The resulting air freshener has a high heat resistance and can be used in high-temperature locations such as the inside of a car.It also has a long-lasting fragrance without deterioration, and does not warp or form bubbles, so it has a good appearance. It is also an excellent fragrance and has extremely high levels of usefulness.

Claims (2)

[Claims] Claim 1: By mixing a photopolymerizable monomer with an oligomer having an unsaturated bond that can be polymerized by light energy, the overall viscosity can be reduced to 100 to 500 at 25°C.
1. A method for producing a photocurable aromatic gel, which comprises preparing a gel base material with a temperature of 0 cps, blending a fragrance into the gel base material, and then irradiating the gel base with light energy. 2. The method for producing a photocurable aromatic gel according to claim 1, wherein a fragrance having a maximum gram extinction coefficient of 1.5 or less in the wavelength range of 290 to 370 nm is used as the fragrance.